Do you have iMessage turned on? Are you signed in to iMessage? Do you have "use as SMS" turned on? If not, go to Settings >Messages> Toggle all those on. If you haven't signed in to iMessage, do that.
Now,
Go to your Messages app. Enter a contact or address at the top. Then tap the little camera icon. Choose "Photo Library" and tap a photo. Hit send.
If you're not getting the option to send a photo, try a hard reset.
Hold the top power/sleep button and the home button at the same time until the Apple logo appears, then release.

Do you have iMessage turned on? Are you signed in to iMessage? Do you have "use as SMS" turned on? If not, go to Settings >Messages> Toggle all those on. If you haven't signed in to iMessage, do that.
Now,
Go to your Messages app. Enter a contact or address at the top. Then tap the little camera icon. Choose "Photo Library" and tap a photo. Hit send.
If you're not getting the option to send a photo, try a hard reset.
Hold the top power/sleep button and the home button at the same time until the Apple logo appears, then release.